Barrel opening cover



FIG. 1 illustrates a top plan view of a barrel opening cover showing our new and ornamental design;

FIG. 2 illustrates a bottom plan view thereof;

FIG. 3 illustrates a top perspective view thereof; and,

FIG. 4 illustrates a bottom perspective view thereof.

The broken lines in the drawings show environment and form no part of the claimed design. 

CLAIM The ornamental design for a barrel opening cover, as shown and described. 